<html>
   <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
   </head>
   <body>
      <form action="forward" enctype="multipart/form-data" method="post" >
         <input type="text" name="username"/><br>
         <input type="file" name="file" id="file"/><br>
         <input type="submit" value="提交"/>
      </form>
   </body>
</html>